1. Field of the Invention
The present invention relates to a device for making the guide-path for an instrument on a patient, particularly for a puncturing needle used in a medical procedure.
2. Description of the Prior Art
The puncturing of different body parts and organs for diagnostic or therapeutic purposes is known. In this way, tissue samples for examination can be obtained. It is often problematic to direct the puncturing needle safely to the desired location, especially when dealing with a relatively small area lying deep under the skin surface.
In preparation for puncturing, it is known to create sectional images of the body area to be punctured with the aid of tomography apparatus, e.g. a computed tomography or a magnetic resonance tomography apparatus. Using these sectional images, the physician determines the area to be punctured and selects the most favorable point and direction of incision. The patient is moved out of the tomography apparatus for puncturing. The point of incision found using the selected sectional image is marked on the patient's body. The physician subsequently inserts the puncturing needle, estimating the angle of incision.
An apparatus for assisting in such procedures is known from German OS 195 01 069, wherein two planar laser beams of different colors are directed onto the patient's body for more exact guidance of a puncturing needle. The line of intersection of the laser beams marks therein the guide path for the puncturing needle. The outlay for such a marking device is relatively significant.